London: Children of obese mothers are more likely to suffer from asthma or wheezing, a new study has claimed.

The increase in the risk ranges from 20 to 30 per cent, compared with women who have a healthy pre-pregnancy weight, the study found.

Lead study researcher Professor Marjo-Riitta Jarvelin of Imperial College London said there was a relationship between increasing maternal weight and increased risk of asthma symptoms.

"The heavier the women, the more the risk of wheezing and asthma-like symptoms," Professor Jarvelin said.

She said: "The children of obese women who have a history of allergy also have a much higher risk of wheezing.

"There is over 3.5 times higher risk of having wheezing, and for current wheezing the risk was over four times higher."

Though the researchers are not sure that obesity causes respiratory symptoms among teenagers, they believe it could be partly to blame for rising rates of asthma.

Past studies have suggested that children of overweight mothers are exposed to increased levels of pro-inflammatory factors in the womb, which could influence their asthma risk.

The new study, published in the Journal of Epidemiology and Community Health, involved almost 7,000 children aged between 15 and 16 years in northern Finland.

Their mothers were asked about their lifestyle, social background and educational achievements when they were 12 weeks' pregnant. Medical data on their height and weight before pregnancy was also examined.

It was found that just over one in 10 of the teenagers still wheezed and one in five had wheezed in the past.